Monitoring the Material Quality of Two-Dimensional Transition Metal Dichalcogenides

Two-dimensional (2D) transition metal dichalcogenides (TMDs), with atomic thickness, strong spin–orbit coupling, enhanced light-matter interactions. and facile quantum control ability, have demonstrated great potential in the applications of nanoelectronics and optoelectronics. The realization of these high-performance applications strongly relies on the production of large-scale TMD films with high quality. Therefore, facile and accurate quality monitoring of TMDs is essential for their future applications. In this Review, we summarized the main defect types in TMD crystals obtained by different synthesis methods, and we discussed recent cutting-edge characterization techniques, including scanning transmission electron microscopy, etching or adsorption, optical spectroscopy, and field-effect transistors. Finally, we provide a short perspective on the future development of quality monitoring techniques for broad 2D materials.